Postage meters find extensive use throughout the world for imprinting postage on objects to be mailed. Postage, of course, is the amount of money or fee required to have the Post Office deliver a mail piece to which the postage is applied to an indicated address. The postage may be applied to a mail piece by a print head enclosed within the postage meter, i.e., directly upon an envelope or upon a label. When postage is printed upon a label, the label is then placed in adhering contact onto an envelope, parcel or other object to be mailed. The postage meter is also capable of printing information in addition to the amount of postage. For example, the postage meter is used for imprinting the date of mailing, the piece number, suitable indicia designating instructions and/or routing information for transport by private carriers, and the like as is well known. Furthermore, if desired, the postage meter can be utilized for the imprinting of yet other forms of labels, such as tax stamps, assuming that govermental approval for such tax stamps is obtained.
A potential problem in the use of imprinted postage is the attempt at fraudulent adulteration of such postage; whereby, in effect, the person adulterating the postage is stealing the value of the postage. A fraudulent impression may enable someone to obtain postage, or in the case of a tax stamp, to avoid paying the tax. The foregoing problems have been overcome by various methods of determining if the postage on a mail piece is genuine through various forms of encryption and apparatus have been designed to implement such methods.